Brass is a copper alloy with zinc as the main additive element, which has a beautiful yellow color and is collectively referred to as brass. The copper-zinc binary alloy is called ordinary brass or simple brass. Brass with more than three yuan is called special brass or complex brass. Brass alloys containing less than 36% zinc are composed of solid solution and have good cold working properties. For example, brass containing 30% zinc is often used to make bullet casings, commonly known as bullet casing brass or seven-three brass. Brass alloys with zinc content between 36 and 42% are composed of and solid solution, of which the most commonly used is the six-four brass with zinc content of 40%. In order to improve the properties of ordinary brass, other elements are often added, such as aluminum, nickel, manganese, tin, silicon, lead, etc. Aluminum can improve the strength, hardness and corrosion resistance of brass, but reduce the plasticity, so it is suitable for seagoing condenser pipes and other corrosion-resistant parts. Tin can improve the strength of brass and the corrosion resistance to seawater, so it is called naval brass and is used for ship thermal equipment and propellers. Lead improves the machinability of brass; this free-cutting brass is often used in watch parts. Brass castings are often used to make valves and pipe fittings, etc.

Bronze originally refers to copper-tin alloys, and later copper alloys other than brass and cupronickel are called bronzes, and are often given the name of the first main added element before the name of bronze. Tin bronze has good casting properties, anti-friction properties and good mechanical properties, and is suitable for manufacturing bearings, worm gears, gears, etc. Lead bronze is a widely used bearing material for modern engines and grinders. Aluminum bronze has high strength, good wear resistance and corrosion resistance, and is used for casting high-load gears, bushings, marine propellers, etc. Beryllium bronze and phosphor bronze have high elastic limit and good electrical conductivity, and are suitable for manufacturing precision springs and electrical contact elements. Beryllium bronze is also used to make non-sparking tools used in coal mines and oil depots.